Combustion engines include at least one combustion chamber into which fuel is provided, typically by a fuel injector. Some fuel injectors, such as common-rail injectors, generate a backflow of fuel that can reach high temperature during engine operation. More specifically, heat is generated as a result of the decompression of the fuel backflow from high pressure to low pressure. The fuel has to be highly pressurized first before being expanded. This thermal energy of the backflow is typically wasted, as the fuel backflow is usually returned directly back to the fuel tank. Better and more efficient fuel management in such fuel systems is therefore desirable.